Northern Ireland is part of the United Kingdom, and covers 5,459 square miles (14,139 kmÂ²) in the northeast of the island of Ireland, about a sixth of the total area of the island. It has a population of 1,685,000 (April 2001) â€” between a quarter and a third of the island's total population. Northern Ireland consists of six of the nine counties of the province of Ulster. In the UK it is generally known as one of its four Home Nations, forming a constituent part of the United Kingdom. Some of these terms have controversial implications in relation to political ideologies concerning the constitutional status of Northern Ireland. The remainder of the island of Ireland is a sovereign state, the Republic of Ireland.

As an administrative division of the United Kingdom, Northern Ireland was defined by the Government of Ireland Act, 1920, and has had its own form of devolved government in a similar manner to Scotland and Wales. The Northern Ireland Assembly is, however, currently suspended. Northern Ireland's legal system descends from the pre-1920 Irish legal system (as does the legal system of the Republic of Ireland), and is therefore based on common law. It is separate from the jurisdictions of England and Wales or Scotland.

Northern Ireland has been for many years the site of a violent and bitter ethno-political conflict between those claiming to represent Nationalists, who are predominantly Catholic, and those claiming to represent Unionists, who are predominantly Protestant. In general, Nationalists want Northern Ireland to be unified with the Republic of Ireland, and Unionists want it to remain part of the United Kingdom. Unionists are in the majority in Northern Ireland, though Nationalists represent a significant minority. In general, Protestants consider themselves British and Catholics see themselves as Irish (see Nationality and Identity below). The campaigns of violence have become known popularly as The Troubles. The majority of both sides of the community have had no direct involvement in the violent campaigns waged. Since the signing of the Belfast Agreement in 1998, many of the major paramilitary campaigns have either been on ceasefire or have declared their war to be over.